Buggy code:
public class Db { public static final String DATABASE_CREATE_USUARIO = ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( "CREATE<seq2seq4repair_space>TABLE<seq2seq4repair_space>" + ( DatosUsuario . TABLE_NAME ) ) + "<seq2seq4repair_space>(" ) + ( DatosUsuario . COLUMN_NAME_NICK ) ) + "<seq2seq4repair_space>varchar2(25)<seq2seq4repair_space>PRIMARY<seq2seq4repair_space>KEY<seq2seq4repair_space>NOT<seq2seq4repair_space>NULL,<seq2seq4repair_space>" ) + ( DatosUsuario . COLUMN_NAME_PASS ) ) + "<seq2seq4repair_space>varchar2(25)<seq2seq4repair_space>NOT<seq2seq4repair_space>NULL,<seq2seq4repair_space>" ) + ( DatosUsuario . COLUMN_NAME_NOMBRE ) ) + "<seq2seq4repair_space>varchar2(25),<seq2seq4repair_space>" ) + ( DatosUsuario . COLUMN_NAME_APELLIDOS ) ) + "<seq2seq4repair_space>varchar2(50),<seq2seq4repair_space>" ) + ( DatosUsuario . COLUMN_NAME_TELEFONO ) ) + "<seq2seq4repair_space>varchar2(15),<seq2seq4repair_space>" ) + ( DatosUsuario . COLUMN_NAME_BDAY ) ) + "<seq2seq4repair_space>varchar2(10),<seq2seq4repair_space>" ) + ( DatosUsuario . COLUMN_NAME_SEXO ) ) + "<seq2seq4repair_space>varchar2(25),<seq2seq4repair_space>" ) + ( DatosUsuario . COLUMN_NAME_FOTO ) ) + "<seq2seq4repair_space>varchar2(500),<seq2seq4repair_space>" ) + ( DatosUsuario . COLUMN_NAME_ACTIVO ) ) + "<seq2seq4repair_space>varchar2(10),<seq2seq4repair_space>" ) + ( DatosUsuario . COLUMN_NAME_TIPO ) ) + "<seq2seq4repair_space>varchar2(15)<seq2seq4repair_space>NOT<seq2seq4repair_space>NULL)" ; public static final String DATABASE_CREATE_GRUPO = ( ( ( ( ( ( ( ( ( ( ( ( ( "CREATE<seq2seq4repair_space>TABLE<seq2seq4repair_space>" + ( DatosGrupo . TABLE_NAME ) ) + "<seq2seq4repair_space>(" ) + ( DatosGrupo . COLUMN_NAME_ID ) ) + "<seq2seq4repair_space>number(6)<seq2seq4repair_space>PRIMARY<seq2seq4repair_space>KEY," ) + ( DatosGrupo . COLUMN_NAME_NOMBRE ) ) + "<seq2seq4repair_space>varchar2(25),<seq2seq4repair_space>" ) + ( DatosGrupo . COLUMN_NAME_DESCRIPCION ) ) + "<seq2seq4repair_space>varchar2(500),<seq2seq4repair_space>" ) + ( DatosGrupo . COLUMN_NAME_IMAGEN ) ) + "<seq2seq4repair_space>varchar2(100),<seq2seq4repair_space>" ) + ( DatosGrupo . COLUMN_NAME_MAXINTEGRANTES ) ) + "<seq2seq4repair_space>number(3),<seq2seq4repair_space>" ) + ( DatosGrupo . COLUMN_NAME_ACTIVO ) ) + "<seq2seq4repair_space>varchar(10))" ; public static final String DATABASE_CREATE_MENSAJE = ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( "CREATE<seq2seq4repair_space>TABLE<seq2seq4repair_space>" + ( DatosMensaje . TABLE_NAME ) ) + "<seq2seq4repair_space>(" ) + ( DatosMensaje . COLUMN_NAME_ID ) ) + "<seq2seq4repair_space>number(6)<seq2seq4repair_space>PRIMARY<seq2seq4repair_space>KEY,<seq2seq4repair_space>" ) + ( DatosMensaje . COLUMN_NAME_TEXTO ) ) + "<seq2seq4repair_space>varchar2(500),<seq2seq4repair_space>" ) + ( DatosMensaje . COLUMN_NAME_DESTINO ) ) + "<seq2seq4repair_space>varchar2(25)<seq2seq4repair_space>NOT<seq2seq4repair_space>NULL,<seq2seq4repair_space>" ) + ( DatosMensaje . COLUMN_NAME_ORIGEN ) ) + "<seq2seq4repair_space>varchar2(25)<seq2seq4repair_space>NOT<seq2seq4repair_space>NULL,<seq2seq4repair_space>" ) + ( DatosMensaje . COLUMN_NAME_NICKUSUARIO ) ) + "<seq2seq4repair_space>varchar2(25)<seq2seq4repair_space>CONSTRAINT<seq2seq4repair_space>fk_nickusuario<seq2seq4repair_space>" ) + "REFERENCES<seq2seq4repair_space>" ) + ( DatosUsuario . TABLE_NAME ) ) + "(" ) + ( DatosUsuario . COLUMN_NAME_NICK ) ) + "))" ; public static final String DATABASE_CREATE_GRUPOUSUARIO = ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( "CREATE<seq2seq4repair_space>TABLE<seq2seq4repair_space>" + ( DatosGrupoUsuario . TABLE_NAME ) ) + "<seq2seq4repair_space>(" ) + ( DatosGrupoUsuario . COLUMN_NAME_NICKUSUARIO ) ) + "<seq2seq4repair_space>varchar2(25)<seq2seq4repair_space>CONSTRAINT<seq2seq4repair_space>FK_NICKUSUARIO1<seq2seq4repair_space>" ) + "REFERENCES<seq2seq4repair_space>" ) + ( DatosUsuario . TABLE_NAME ) ) + "(" ) + ( DatosUsuario . COLUMN_NAME_NICK ) ) + "),<seq2seq4repair_space>" ) + ( DatosGrupoUsuario . COLUMN_NAME_IDGRUPO ) ) + "<seq2seq4repair_space>number(6)<seq2seq4repair_space>CONSTRAINT<seq2seq4repair_space>FK_IDGRUPO<seq2seq4repair_space>" ) + "REFERENCES<seq2seq4repair_space>" ) + ( DatosGrupo . TABLE_NAME ) ) + "(" ) + ( DatosGrupo . COLUMN_NAME_ID ) ) + "))" ; public static final String DATABASE_ADD_CONSTRAINT_USUARIO = ( ( ( ( ( "ALTER<seq2seq4repair_space>TABLE<seq2seq4repair_space>" + ( DatosUsuario . TABLE_NAME ) ) + "<seq2seq4repair_space>ADD<seq2seq4repair_space>(CONSTRAINT<seq2seq4repair_space>" ) + ( DatosUsuario . CONSTRAINT_USUARIO ) ) + "<seq2seq4repair_space>PRIMARY<seq2seq4repair_space>KEY<seq2seq4repair_space>(" ) + ( DatosUsuario . COLUMN_NAME_NICK ) ) + "))" ; public static final String DATABASE_ADD_CONSTRAINT_GRUPO = ( ( ( ( ( "ALTER<seq2seq4repair_space>TABLE<seq2seq4repair_space>" + ( DatosGrupo . TABLE_NAME ) ) + "<seq2seq4repair_space>ADD<seq2seq4repair_space>(CONSTRAINT<seq2seq4repair_space>" ) + ( DatosGrupo . CONSTRAINT_GRUPO ) ) + "<seq2seq4repair_space>PRIMARY<seq2seq4repair_space>KEY<seq2seq4repair_space>(" ) + ( DatosGrupo . COLUMN_NAME_ID ) ) + "))" ; public static final String DATABASE_ADD_CONSTRAINT_MENSAJE = ( ( ( ( ( "ALTER<seq2seq4repair_space>TABLE<seq2seq4repair_space>" + ( DatosMensaje . TABLE_NAME ) ) + "<seq2seq4repair_space>ADD<seq2seq4repair_space>(CONSTRAINT<seq2seq4repair_space>" ) + ( DatosMensaje . CONSTRAINT_MENSAJE ) ) + "<seq2seq4repair_space>PRIMARY<seq2seq4repair_space>KEY<seq2seq4repair_space>(" ) + ( DatosMensaje . COLUMN_NAME_ID ) ) + "))" ; public static final String DATABASE_GRUPO_SEQUENCE = "CREATE<seq2seq4repair_space>SEQUENCE<seq2seq4repair_space>" + ( DatosGrupo . SEQUENCE_GRUPO_ID ) ; public static final String DATABASE_GRUPO_NEXT_ID = ( "SELECT<seq2seq4repair_space>" + ( DatosGrupo . SEQUENCE_GRUPO_ID ) ) + ".NEXTVAL<seq2seq4repair_space>FROM<seq2seq4repair_space>DUAL" ; public static final String DATABASE_MENSAJE_SEQUENCE = "CREATE<seq2seq4repair_space>SEQUENCE<seq2seq4repair_space>" + ( DatosMensaje . SEQUENCE_MENSAJE_ID ) ; public static final String DATABASE_MENSAJE_NEXT_ID = ( "SELECT<seq2seq4repair_space>" + ( DatosMensaje . SEQUENCE_MENSAJE_ID ) ) + ".NEXTVAL<seq2seq4repair_space>FROM<seq2seq4repair_space>DUAL" ; public static final String DATABASE_CREATE_NOTIF = ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( "CREATE<seq2seq4repair_space>TABLE<seq2seq4repair_space>" + ( DatosNotificacion . TABLE_NAME ) ) + "<seq2seq4repair_space>(" ) + ( DatosNotificacion . COLUMN_NAME_ID ) ) + "<seq2seq4repair_space>NUMBER(6)<seq2seq4repair_space>PRIMARY<seq2seq4repair_space>KEY<seq2seq4repair_space>NOT<seq2seq4repair_space>NULL," ) + ( DatosNotificacion . COLUMN_NAME_USER ) ) + "<seq2seq4repair_space>VARCHAR2(25)<seq2seq4repair_space>CONSTRAINT<seq2seq4repair_space>" ) + ( DatosNotificacion . FK_USER_NOTIF ) ) + "<seq2seq4repair_space>REFERENCES<seq2seq4repair_space>" ) + ( DatosUsuario . TABLE_NAME ) ) + "(" ) + ( DatosUsuario . COLUMN_NAME_NICK ) ) + ")" ) + ( DatosNotificacion . COLUMN_NAME_TEXT ) ) + "<seq2seq4repair_space>VARCHAR2(500),<seq2seq4repair_space>" ) + ( DatosNotificacion . COLUMN_NAME_DATE ) ) + "<seq2seq4repair_space>DATE)" ; public static final String DATABASE_NOTIF_SEQUENCE = "CREATE<seq2seq4repair_space>SEQUENCE<seq2seq4repair_space>" + ( DatosNotificacion . SEQUENCE_NOTIF_ID ) ; public static final String DATABASE_NOTIF_NEXT_ID = ( "SELECT<seq2seq4repair_space>" + ( DatosNotificacion . SEQUENCE_NOTIF_ID ) ) + ".NEXTVAL<seq2seq4repair_space>FROM<seq2seq4repair_space>DUAL" ; public static String addNotif ( String usuario , String texto , Date fecha ) { } public static String getPerfil ( String usuario ) { } public static String getNotif ( ArrayList < String > usuarios ) { <START_BUG> String result = ( ( ( ( ( ( "SELECT<seq2seq4repair_space>" + ( DatosNotificacion . COLUMN_NAME_USER ) ) + ",<seq2seq4repair_space>" ) + ( DatosNotificacion . COLUMN_NAME_TEXT ) ) + ",<seq2seq4repair_space>" ) + ( DatosNotificacion . COLUMN_NAME_DATE ) ) + "<seq2seq4repair_space>FROM<seq2seq4repair_space>" ) + ( DatosNotificacion . TABLE_NAME ) ; <END_BUG> result += ( ( ( DatosNotificacion . COLUMN_NAME_USER ) + "<seq2seq4repair_space>'" ) + ( usuarios . get ( 0 ) ) ) + "'<seq2seq4repair_space>" ; if ( ( usuarios . size ( ) ) > 1 ) { for ( int i = 1 ; i < ( usuarios . size ( ) ) ; i ++ ) { result += ( ( ( "OR<seq2seq4repair_space>" + ( DatosNotificacion . COLUMN_NAME_USER ) ) + "<seq2seq4repair_space>'" ) + ( usuarios . get ( i ) ) ) + "'<seq2seq4repair_space>" ; } } result += ( "<seq2seq4repair_space>ORDER<seq2seq4repair_space>BY<seq2seq4repair_space>" + ( DatosNotificacion . COLUMN_NAME_DATE ) ) + "<seq2seq4repair_space>DESC" ; return result ; } public static String getUsuarios ( ) { } }

Fix:
String result = ( ( ( ( ( ( ( "SELECT<seq2seq4repair_space>" + ( DatosNotificacion . COLUMN_NAME_USER ) ) + ",<seq2seq4repair_space>" ) + ( DatosNotificacion . COLUMN_NAME_TEXT ) ) + ",<seq2seq4repair_space>" ) + ( DatosNotificacion . COLUMN_NAME_DATE ) ) + "<seq2seq4repair_space>FROM<seq2seq4repair_space>" ) + ( DatosNotificacion . TABLE_NAME ) ) + "<seq2seq4repair_space>WHERE<seq2seq4repair_space>" ;